I've made a few photos of a vespiary. Click here to see them. They're nothing much.

These were wasps, so I stood a good metre and a half from them. With my VR 18-200 fully extended, I tried several combinations of apertures, during the course of two days. Still, I ended up with not so sharp photos.

I'm a little frustrated with the results. My previous try, with a bee, produced photos that obviously aren't sharp in a "pro" sense, but look quite good to me.

hmmm, does seems unsharp but it doesn't seem out of focus. According to the review of this lens on this site it should be very sharp but only relative to a superzoom. Macro shots is very demanding of the lens.

Luis, I'm just screening your shots.
- 308 seems to me perfectly sharp at the lower hanging wasp near the door. The depth of field shrinks to the square of the increase in magnification. That is certainly the reason, why you have such a shallow depth of field (dof) here, although you shot at f8!
- with 303 the focus seems to be the upper right corner of the doorway. This (incl. the crack) seems perfectly sharp.
- 307 same as 303.
So watch out very carefully where the focus is with macro shots.
B.t.w.: although the VR 18-200mm is a gem, it certainly is not the highest-IQ in close-ups!

Luis, you want to know more about my assertion that[quote=tombomba2]The depth of field shrinks to the square of the increase in magnification[/quote]
Well I don't have the exact formula for calculating dof, but my assertion is an approximation of dof-tables. Meaning:
The dof (for "very critical viewing" = at a DIN A3 (!) print from 25cm distance) for a subject 4m away from you shooting with a 80mm lens at f8 is approx. 20cm, the magnification is approx. 80mm:4m=1:50. If you shoot the subject with the same lens/setting at 80cm distance, magnification is roughly 1:10 so the subject is now 5 times bigger than in the previous shot. The dof now is 5²=25 times smaller than before: below 1cmThis is an unavoidable trap that many people step into when shooting close-ups. Even stoping down to F16 only brings the dof up to something below 2cm

The depth of field shrinks to the square of the increase in magnification

Well I don't have the exact formula for calculating dof, but my assertion is an approximation of dof-tables. Meaning:
The dof (for "very critical viewing" = at a DIN A3 (!) print from 25cm distance) for a subject 4m away from you shooting with a 80mm lens at f8 is approx. 20cm, the magnification is approx. 80mm:4m=1:50. If you shoot the subject with the same lens/setting at 80cm distance, magnification is roughly 1:10 so the subject is now 5 times bigger than in the previous shot. The dof now is 5²=25 times smaller than before: below 1cmThis is an unavoidable trap that many people step into when shooting close-ups. Even stoping down to F16 only brings the dof up to something below 2cm